peters



21 Shem-Sheet 1. BOYD & HART.

Hot-Air Furnace.

No. 97,347. Patented Nov. 3 0, 1869.

0 gym M We 2 Sheets-Sheet 2.

BOYD & HART.

Hot-A ir Furnace.

-Patented Nov. 30, 1869.

Tm 07 03-07 RM wwqni gww Q M w Km a W Z i dined swa ROBERT BOYD ANDJAMES OJHA RT, OF ROCHESTER, NEW YORK.

Letters Patent No. 97 ,347 dated Not-ember 30, .1869.

HOT-AIR FURNACE.

The Schedule referred to in these Letters Patent and making part of thesame.

ing it through fines passing down on each side of the entrance-way tothe ash-pit into an air-chamber extending entirely under the furnace,and thence directly into a hot-air space, completely surrounding andenclosing the sides of the ash-pit, from whence it is distributed underthe fire by means of a series of apertures pierced in the inner wall ofthe ash-pit immediately under the grate-bars. The object of this part ofour invention is to heat the current of air feed ing the fire, and ourdevices for the purpose are improvements upon devices heretofore in use.

The improvements consist, mainly, in so constructing, arranging, anddisposing the air-fines and spaces as that said tines and spaces shallcover and include the entire exterior radiating-surtace ot the ash-pit,

instead of a part thereof, whereby the air becomes more fully heatedthan where it passes over a portion only of said surface.

The second part of our invention relates to the formation of a seriesot'serrat-ures upon the edges of the draught-apertures in the dampers ofa stove or furnace. The object of this part of our invention being toobtain a more perfect control over the admission of air through thedraught-openings, and the nicest possible adjustment thereof.

Figure 1, of the accompanying drawings, is an elevation of the front ofour improved furnace, illustrating the position of the damper-doors;

Figure 2, a side elevation of the base thereof, (including the ash-pitand grate,) with a portion of the outer casing broken away, toillustrate the direction of the draught therein;

Figure 3, a horizontal section of the base in the line a: x of fig. 2;

Figure 4, a horizontal section in the line y y of fig.

2, with a portion of the floor of the ash-pit broken away, to illustratethe course of the draught through the air-space beneath;

Figure 5, a vertical transverse section in the line .7 z of fig. 3; and

Figure 6, a detached view of our improved serrated graduating damper.

A is the ash-pit of the furnace.

B, the grate.

O, the walls.

D, the door of the ash-pit, and

1'), the entrance-way into the same.

F, an outer casing, so encircling the wall of the ashpit, and of theentrance-way E thereto, as to form and enclose an air-space or chamber,G, about the same.

H, an air-space or chamber formed under the ashpit and the entrance-waythereto, by an'extension oi the outer casing F below the level of theash-pit floor.

K K, partitions, forming flue-spaces G G, on each Side of theentrance-way E to the ash-pit A, by sepa} rating said spaces from thechamber G encircling the ash-pit.

L, the door of the ash-pit.

M M, dampers or dranght-d'iors opening directly into the spaces G G,partitioned ofl' from the encircling air-chamber G.

N, a flue placed on top of the entrance-way into the ash-pit, andextending from side to side thereof, corn-j municating with a frontdamper or draught door, P.

Apcrtnres s s, figs. 2 and 3, are pierced at each end of this flue 1,opening into the spaces G G.

Apertures t t, figs. 2 and 4, are also pierced in the bottom of thespacesG' G, which, opening directly into the air-chamber H, extendingunder the ash-pit, convert said spaces into air-fines.

\Vings or curved partitionplates, 0 U, fig. 4, are inserted between the.bottom of the ash-pit and the floor of the air-chamber beneath,converging toward the centre from lateral points coincident with thejuncture of the entrance-way E and ash-pit A, as illustrated in fig. 4of the drawings.

These wings serve to throw the currents of air entering the chamber orair-space N, through the open-. ings at t i toward the centre thereof.

Free communication is established between the airchambcrs H and G, bymeans in a continuous series of openings, W W, figs. 4 and 5, of thebottom of the encircling chamber G, conmmnicating directly with theairspace Hbelow.

The dampers or draught-doors are constructed with one of the edges ofeach draught-opeuing' serrated, substantially as illustrated in thedrawings, figs. 1 and- 6. Either the edge of the stationary platesthrough which the drauglit-opcnings are pierced are serrated, asillustrated, or these are left straight and unbroken, and thedamper-doors covering said openings are serrated, the required ninety ofadjustment in the draught-openinghcing sin' ilarly obtained in eithercase.

The operation of our improved furnace is as follows:

After a fire has been properly kindled upon the grate B, the door D,leading into the ash-pit, is closed to prevent a passage of air throughthe ash-pit, and make it, in fact, comparatively air-tight, and one ormore of the damper-doors P and M M, over and on each side of the ash-pitdoor, are opened to admit the necessary supply of air to supportcombustion.

The currents of air entering through the upper draught-door P, pass tothe right and left, through the flue N, and down through the apertures ss at each end thereof, into the side fines G G. From its peculiarposition, and its proximity to the fire-box of the 4 the ash-pititself,) deriving heat therefrom, and thenes'eapes through the openingsW W W into the chamber G, surrounding the ash-pit,where it becomes stillmore highly heated, and is then discharged in its heated stateimn'iediately under thegrate-bars to sustain the combustion of the fuelthereon.

By thus conveying the draught of air for the furnace under and aroundthe entire exterior surface of the ash-pit, all the heat radiatingtherefrom, and otherwise lost, is utilized in heating said draught andobtaining aconsequent economy in the consumption of fuel in the furnace.

The side doors M M may be dispensed .with and the upperdraught P alonebe used, or where it is not convenient to introduce an upper flue, N,the side dampers M M will suffice. By providing each draughtopening withserrated graduating dampers M and P, we are enabled to regulate theadmission of air through the openings with a nicety hitherto unattainedin stoves and furnaces, and we contemplate the application of thesedampers to all manner-of draught-open-, ings where the supply of airrequires close adjustment.

We do not claim heating the air to support combustion in the furnace,nor do we claim passing the draught for. this'furnace through anenclosed space underthe ash-pit.

Ve claim, as our invention- 1. A draught-opening and flue N, arrangedover the entrance-wayto the ash-pit of the furnace, and communicatingwith lines G G formed on either side of H, extending under the bottom ofthe ash-pit, and a flue-chamber G completely surrounding the same, andfrom whence the heated draught is discharged under the grate-bars of thefurnace, all substantially in the manner herein set'forth.

directly with said side flues G, and combined with substantially asherein described.

of the ash-pit A, when combined with the air-space H below, and providedwith a series of suitable inletapertures W W below, and discharge-ventsabove, substantially as hereiudescribed.

4. A graduated damper having the edges of one or more of the plates,(either stationary or movable,) controlling the admission of air,serrated, substantially as herein described. 7

The foregoing specification signed by us, this 15th day of October,1869.

ROBT. BOYD.

J AS. '0. HART.

, Witnesses:

HENRY H. Mouse, OHAs. W. Tnocrrnn.

said entrance-way, in combination with an air-space 2. The sidedraught-openings M M, communicating the said lower air-space H, andencircling chamber G,

3. The chamber G, completely enclosing the sides I

